Control Function and Current Limiter Function

Pin Descriptions

No. 5975-4/8

LB1999M

Control Characteristics

Control Limiter Characteristics

Slope: 0.50 A/V (typical)

Pin No.

Pin

Function

Equivalent circuit

Input used when the FG amplifier is used as an inverting

and this pin.

3

Noninverting input used when the FG amplifier is used as a

differential input amplifier. No bias is applied internally.

4

FG amplifier output. There is an internal resistive load.

5

Control reference voltage. While this pin is set to about

0.43

applying a voltage from a low-impedance circuit.

(The input impedance is about 4.3 k

Ω).

6

FGS

Speed control loop frequency characteristics correction.

9

FC

Speed control input. The control implemented is fixed current

drive controlled by current feedback from Rf.

Gm = 0.58/V (typical) when Rf = 0.5

Ω.

7

CTL

Current limiter function control. The output current can be

varied linearly by applying a voltage to this pin.

The slope is 0.5 A/V (typical) when Rf = 0.5

Ω.

8

LIM

U phase Hall element inputs.

Logic high is defined as states where IN+ > IN–.

10

11

V phase Hall element inputs.

Logic high is defined as states where IN+ > IN–.

12

13

W phase Hall element inputs.

Logic high is defined as states where IN+ > IN–.

14

15

Power supply for all internal blocks other than the output

block. This voltage must be stabilized so that noise and ripple

do not enter the IC.

16

Continued on next page.